Building materials incorporated with hydrophobic silicone resin(s)

Abstract

An inorganic matrix building material with enhanced water impermeability is prepared by curing an inorganic curable matrix and at least one particulate hydrophobic silicone resin substantially uniformly incorporated within the matrix, the at least one hydrophobic silicone resin being selected from the group consisting of a TD resin, an MQ resin, an MT resin, an MQT resin, and combinations thereof. In certain particular instances, the at least one hydrophobic silicone resin is a TD resin. The curing takes place at elevated temperature, optionally at elevated pressure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. provisional application Ser. No. 61 / 049,638, filed on May 1, 2008.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to autoclaved inorganic building materials with solid particulate hydrophobic silicone resin(s) uniformly incorporated therein, and to processes of making the same.[0004]2. Background Art[0005]Conventional inorganic matrix building materials, including artificial stones, concrete blocks, and fiber-reinforced concrete boards, can be subject to efflorescence and freeze thaw damage which are commonly known to be associated with water absorption into and through the building materials. For example, moisture penetration into even natural permeable stone substrates can cause these materials to expand, to crack, and to cause ultimate deterioration of the structure of the building materials. Water moisture also greatly induces microbial invasion ...

AI Technical Summary

Benefits of technology

[0015]It is an object of the present invention to provide inorganic matrix building materials wherein efflorescence is minimized, resistance to freeze / thaw cycles is enhanced, and the hydrophobing compositions and processes are simple and economical. These and other objects are surprisingly achieved through the use of building materials based on an inorganic matrix, into the raw material mix of which is incorporated at least one solid hydrophobic particulate silicone resin, and the mixture thereof is subsequently autoclaved to produce a building material product which is uniformly hydrophobic, yet which is capable of construction with standard mortars and the like.

Problems solved by technology

Conventional inorganic matrix building materials, including artificial stones, concrete blocks, and fiber-reinforced concrete boards, can be subject to efflorescence and freeze thaw damage which are commonly known to be associated with water absorption into and through the building materials.

For example, moisture penetration into even natural permeable stone substrates can cause these materials to expand, to crack, and to cause ultimate deterioration of the structure of the building materials.

Water moisture also greatly induces microbial invasion and attack, often resulting in unsightly discoloration.

Masonry materials based on inorganic binders may suffer the same type of degradation due to freeze / thaw conditions, resulting in what is known as spalling and cracking.

Thus, hydrophobicizing the surface following construction only limits ingress of water from the outside surface.

Water traveling vertically may still enter the masonry product and cause efflorescence and freeze / thaw damage.

However, if all sides of the construction material are hydrophobicized prior to construction, the hydrophobic coating may prevent adherence of mortar, or subsequent application of plasters, renders, stucco, etc.

The above-described hydrophobing surface coating compositions or processes for rendering a surface hydrophobic, however, have met with limited use.

Moreover, even before the primer or the base coating is deposited onto the surface, the surface has to be subjected to laborious pretreatment with water or acid vapor, or by sandblasting.

This is particularly so when the building materials have been exposed to the atmosphere for quite some time and thus have been rendered dirty by dust or waste gases.

All the above-described methods of hydrophobicizing building materials also suffer from complex methods of preparation and application, and are also generally subject to discoloration after extended exposure.

The pre-treatment steps along with the base coating applications thus inevitably cause the use of these hydrophobing surface coatings to be more time consuming, more labor intensive, and much less cost effective.

The organosilicone based compositions described above have proven useful in hydrophobicizing existing masonry work such as building facades, retaining walls, tunnels, etc., but are only capable of hydrophobicizing the surface.

Applications involving stiff creams are labor intensive, and the presence of organic solvents in some of the compositions described is not desirable in view of present day limitations on VOCs.

These compositions reduce, but do not eliminate, freeze-thaw damage, and may be subject to discoloration after long term exposure.